Mass vaccination is the only way to stop transmission, of course, you just can’t have some people vaccinated and others not, vaccines don’t work like that. The exemptions have never been very deep (very few takers each year), but if they exceed something like 5%, then an adjustment must be made. Washington state for example, revoked personal and philosophical exemptions for MMR vaccines after an outbreak. Religious exemptions are still allowed, but those have a much higher bar than a philosophical exemption. Medical exemptions are always allowed, they are one major reason why most everyone else needs to get vaccinated in the first place (because people who can’t get the vaccine are at risk from transmission).
I guess one could argue that everyone that wants to should get vaccinated to better protect those who don’t want to be vaccinated. That makes sense, but hardly seems fair.
Why would that be any different than your preferred political party/politician telling you to get vaccinated?
Just because you don't agree with someone on some (many?) topics, doesn't mean you can't ever agree with them.
We're talking about well established scientifically backed public health advice. It doesn't matter who most recently repeated the advice, it's the advice itself that's important.
For example the creation of the no fly list, red flag laws, drug laws, civil asset forfeiture, hate crime laws, etc.
Laws have a tendency to get divorced from the situation that created them over the many years but seldom are repealed when their original cause is gone.
As such it is often very likely that my political enemy or your political enemy will have the power of those laws.
This just like development one must always think of the edge cases and error path not just the happy path.
Because you've indicated you oppose this vaccine mandate.
We're discussing a specific use of an already existing piece of legislation (Emergencies Act). There's no additional power granted here, the act was pre-existing, it's being applied.
You certainly may take issue with the fact the Emergencies Act could be used for nefarious purposes i.e. that the scope is too large. That's likely a valid concern. Sadly, most laws and legislations are open to interpretation and susceptible to abuse.
However, if this mandate were to be rolled back, the Emergencies Act isn't going anywhere. The Emergencies Acts is still sitting there available to future leaders.
Let's suppose you think a Covid vaccine mandate is a good thing, but you're ideologically opposed to it coming into force via an act that could be abused. Firstly, you're most certainly not on the same page as the majority of people opposing this mandate.
Secondly, what's your plan? Get rid of the Emergencies Act and come up with new legislation for a vaccine mandate, in record time, and with no holes in it, all the while people are unnecessarily dying, hospitals are unnecessarily overloaded and there's unnecessary economic damage... for ideological reasons?
Your appraisal is an example of the slippery slope fallacy. The only slippery slope is encouraging people to evaluate policies by who is proposing them rather than whether the policy is beneficial. Then the person who is proposing policy can get away with policies that are more and more in their interest and less in mine. As long as the standard of evaluating policy by whether it is beneficial is upheld, there is no slippery slope.
Because whenever the government does something, or is given the ability to do something, whether de jure, or de facto, I ask myself "Would I feel comfortable with my worst political enemy having the power to do this?"
EDIT: The answer I was responding to edited his answer before I finished posting, so the original question was just. "Why do you opposse vax mandates?" My answer still stands.